|
Is there enough scientific proof for umbilical cord blood banking to be offered as an effective regenerative medicine/cure?
Traditionally, bone marrow transplants have always been an acceptable and successful treatment for blood-related illnesses. Stem cells from cord blood are much easier to get because they are readily obtained from the placenta at the time of delivery. Harvesting stem cells from bone marrow requires a surgical procedure, usually under general anesthesia, that can cause post-operative pain and poses a small risk to the donor.
A broader range of recipients may benefit from cord blood stem cells. These can be stored and transplanted back into the donor, to a family member or to an unrelated recipient. For a bone marrow transplant to succeed, there must be a perfect match between the donor and the recipient. When stem cells from cord blood are used, the donor cells appear more likely to ‘take’ or engraft, even when there are partial mismatches.
Graft-versus-Host-Disease (GVHD) is a common complication of bone marrow transplants where the source of the stem cells is a family member or unrelated donor. GVHD occurs when the donor cells see the recipient’s cells as foreign and causes an immune response which attacks the recipient’s cells. This can result in failure of engraftment and in severe cases, death.
This appears to occur less frequently with cord blood than with bone marrow. Even with a 66% match in an umbilical cord stem cell transplant, the rate of GVHD is significantly lower than in a perfect bone marrow transplant.
There is a 1 in 40,000 chance of finding a perfect match and 30%-40% of individuals requiring a donor never find one. Donors can be located within 4 months for about 50% of patients. Banked stem cells from umbilical cord blood can be more readily available, and this can be especially crucial for patients with severe cases of leukemia, anemia or immune deficiency who would, otherwise, die before a match can be found.
In addition, some studies suggest that cord blood may have a greater ability to generate new blood cells than bone marrow. Ounce for ounce, there are nearly 10 times as many blood-producing cells in cord blood. This fact suggests that a smaller number of cord blood cells are needed for a successful transplantation.
Umbilical cord blood is a rich source of blood-forming stem cells and have to date been used to treat a number of blood-related illnesses.
It is the renewing properties of the stem cells which allow them to be used as a treatment. The diseased cells must be completely removed by chemotherapy and/or radiation. This process also kills off all the healthy cells. The stem cells can then be given intravenously to the patient and they will engraft and build a complete new blood and immune system and maintain it for years to come.
Umbilical cord blood stem cells also offer some exciting possibilities for treating certain genetic diseases, especially those involving the immune system.
The number of transplantations performed annually is increasing, and although children constitute the largest group of recipients, adults now account for about one third of recipients. About two thirds of transplants are used in patients with leukemia, and about one quarter in patients with genetic diseases. Although exact statistics are not available, 6,000 cord blood transplantations have now been performed worldwide, primarily in the United States, Western Europe, Japan and Australia.
Sylvana Brannon, is managing director for Smart Cells International (Malta)
The short answer to this question is probably yes. There is mounting evidence that umbilical cord blood can be used to treat various bloods disorders and there is ongoing research to treat other conditions as well. What there is no strong evidence for is that one need use the stem cells obtained from one’s own umbilical cord in order to cure oneself, which is the rationale behind taking cord blood from babies in order to store it for an eventual future necessity.
Whilst there has been considerable moral controversy on stem cells obtained from embryos, one can obtain stem cells from umbilical cord blood just after the delivery process. Indeed these stem cells are not pluripotent as embryonic ones, that is, they cannot form all tissues of the body. They are mostly specific to blood cells and therefore blood disorders.
What is becoming controversial is private blood banking, where pregnant mothers are asked to store their cord blood against a fee. In Malta this fee is around Lm800. The European Group on Ethics had done a survey and issued a statement back in 2003 following such concerns. It recommends caution in this area and certainly advises government to legislate against such form of banking in the case of for-profit banks. Conversely not-for-profit banks may be encouraged on the basis of altruism and sharing. It must be understood that in the case of for-profit banking, the cord blood will only serve the person who is storing it. No one else can benefit. The European Ethics Group therefore is of the opinion that any banking should be government backed and although not wishing to stifle free enterprise, this should be balanced against the principles of justice and solidarity.
In fact the evidence till today, whereby people have benefited from cures for diseases by the use of stem cells from cord blood has been of the type where the cord blood was not that of the patient. There is no scientific evidence that the use of one’s own cord blood is any better than the use of cord blood from other sources. Therefore the group was of the opinion that pressure on parents to store the cord blood of their babies was certainly not justified. Perhaps the only justified cases would be where blood disorders exist in families; especially in the case of rare genetic diseases.
A European network of cord blood banks does exist; the idea being to have a banking system in which countries may benefit as a group. Therefore someone from Malta may immediately get cord blood from abroad.
The issue therefore ‘is not’ about choice. Informed consent is not an easy process and should be done only by professionals. ‘Informed’ means giving all information, especially the above. Certainly trying to persuade parents into potential benefits is not just information at all. Informed consent also involves seeing that the parents are understanding fully what they are doing and are giving a voluntary consent, which means free from coercion, manipulation or persuasion. Last but not least they must be competent. Certainly pregnancy is a vulnerable period and the feeling that parents may think they are not making the best choices for their children makes competence questionable to say the least unless they are armed with the true, unbiased facts.
Pierre Mallia is director at the Centre for Bioethics, University of Malta
|
